Generally, early detection of serious diseases such as cancers and cardiovascular diseases is crucial to patient outcome and potentially survival. Consequently, identification and detection of certain biomarkers indicative of the presence of disease has been an important area of research. For example, irregular expressions of microRNA sequences (“miRNA”) are an early indicator of many conditions such as cancer and cardiovascular disease. Individual irregularities are associated with particular conditions and used to identify the particular condition. Early detection can enable doctors to identify the type of disease and design a treatment strategy based upon the type and progression of the disease. The ability to monitor such small-molecule biomarkers can also assist in tracking treatment effectiveness during the treatment program as well as monitoring for recurrence.
Currently, detection of these biomarkers is expensive and time consuming. A cost-effective, portable method and apparatus for detecting target molecules, such as biomarkers, would facilitate diagnosis and treatment of a variety of conditions. Home-use prescreening devices would be a particular application.
Current options for detecting miRNA biomarkers include plasmonic optical sensors. Such sensors either required high-intensity and expensive laser light sources or expensive optical sensors due to the weak coupling between low-intensity light and surface plasmonic waves of nanoparticles. Current nanofabrication technologies required to produce the sensors are expensive and do not lend themselves to low-cost large-volume production.
Inexpensive method and apparatus are therefore essential for commercial realization of diagnostic devices based on miRNA biomarker profiling.